Dendritic cells (DCs) stand out as a highly promising tool for triggering immune responses in cancer immunotherapy. DCs are recognized as potent antigen-presenting cells (APCs) which excel in generating robust immune reactions and play a pivotal role in connecting the innate and adaptive arms of the immune system. Consequently, DC-based cancer immunotherapy seeks to leverage these distinctive qualities to enhance the battle against cancer. Over the past decades, extensive research has focused on developing immunotherapeutic strategies against cancer through vaccination. To achieve this goal, a comprehensive understanding of DC immunobiology, the regulation of innate and adaptive immune systems, the tumor microenvironment (TME), and the integration of cutting-edge scientific advances is imperative to unlock their significant antitumor immunotherapeutic potential. This chapter concentrates on delving into various aspects of DC immunobiology, including their origin, localization, unique properties, distinct subsets, and their connection to innate and adaptive immunity. Additionally, it explores the contemporary concept of cancer immunotherapy and sheds light on insights derived from clinical trials involving DC vaccines. Ultimately, the chapter outlines future perspectives for this burgeoning field.